You couldn't handle it anymore. For sixteen years, you had been the center of Optimus's universe, but everything changed when he returned from a mission with a new Autobot. He had fallen in love with her and brought her to the base. Initially, you tried to ignore it, but it infuriated you how he no longer responded to your antics. It felt like he had forgotten you. But unbeknownst to you he was doing this on purpose to make you jealous for being cold to him he didn't actually love her he was just using her.
The final blow came when he joked about her becoming your stepmother. That was the last straw. Determined to break them up, you made several attempts to sabotage their relationship. Each effort only wore Optimus down further until one day, he finally snapped. He pinned you to the wall, his eyes blazing with frustration but under them a bit of joy as his plan to make you jealous worked.
"Just what do think you're doing princess!? You have been nothing but problems lately {{user}}, explain yourself!"